NASA Johnson Space Center
Oral History Project
Edited Oral History Transcript
Interviewed by Jennifer Ross-Nazzal
Houston, Texas – 27 May 2010
photographs were provided by the NASA JSC Imagery Repository and Tom
Moser. [Photo Gallery]
is May 27th, 2010. This oral history interview with Tom Moser is being
conducted in Houston, Texas for the NASA Johnson Space Center Oral History
Project. The interviewer is Jennifer Ross-Nazzal, assisted by Rebecca
Wright. Thanks again for taking time out of your schedule today to meet
Moser: My pleasure.
certainly appreciate it. Last time you spent some time talking about
the thermal protection system for the Space Shuttle. I just had a couple
more nontechnical questions, but important questions. Would you tell
us about the difficulties you faced attaching the tiles to Columbia?
Moser: Sure. Back
up just a bit—the thermal protection system was unique in the
fact that it had to be designed for reuse for 100 missions. We knew
we’d have a lot of repairs, so we focused on lightweight material
that had the thermal performance that was necessary and enough durability,
but at the same time protect the structure—in this case the aluminum
structure—to a temperature less than 350 degrees and the outer
surface in the neighborhood of about 2,500 degrees Fahrenheit [on the
tiles]. So it had to be an insulator and perform for multiple missions.
We knew that the attachment of the tiles to the Orbiter was going to
be a problem, because aluminum being the primary structure, it expands
and contracts a lot. The tiles essentially had no expansion and contraction
in a relative sense. We put something between them called the strain
isolation pad, or the SIP. The way it was attached, there was a layer
of adhesive put on the vehicle, and the tile had the SIP bonded to it
with the same type of adhesive, and then we would bond the tile to the
structure. That was it. It was not complicated, and it worked beautifully
for expansion and contraction.
The strain isolation pad was just a loosely woven felt material. Believe
it or not, the same felt that Stetson hats [were] made of. This loosely
woven felt did [the job] beautifully. To keep the felt together, [i.e.]
give it some integrity, every [few inches] a stitch put through [the
felt. This was so] it would not come unraveled. Well, when you attach
a tile to the SIP, which is attached to the structure, and something
tends to pull the tile away from the structure—like aerodynamic
loads or vibration—all these little individual stitches acted
as a stiff spot.
When you think about pulling up on a tile as you try to pull it off
of the structure, like the aerodynamic loads would do, then these little
stiff spots would cause a stress concentration, or it would cause the
bond to fail right there. When that happened, being a very [brittle
and] fragile material that the silica fiber is, then [the failure] would
propagate. So once you started a failure—it’s like a crack
in the windshield of your car. Once those suckers start, they just go.
That’s the way these little cracks would [propagate], and all
of a sudden you’d lose the bond integrity.
We said, “Oh my goodness!” The way we found it, believe
it or not, we were doing some aerodynamic tests with the tiles on a
structure at different airloads. We bonded some tiles to the speed brake
of a T-38 aircraft. The objective was to deploy the speed brake so that
the tiles got a very large aerodynamic load. We calculated [the loads]
we wanted [to simulate], and lo and behold, [some] tiles came off. When
something comes off of an aircraft, that’s a major deal because
now you’re dealing with the FAA [Federal Aviation Administration]
and everyone else, any time something comes loose from an aircraft.
Us grunt engineers were trying to say, “We think we need more
tests, because some of these conditions we haven’t tested.”
The focus [had been] on the thermal performance, “Yes, we hear
you strength integrity guys, but we’ll deal with that at some
point.” This failure on the T-38 caused a major management focus
because they had to sign off on this FAA stuff that [documented] we
had an object come off an airplane.
That let us highlight the characteristics of this bond [attachment of
the tiles to the orbiter]. Then we started with the solution process.
“What do we do to dissipate this peak in load underneath the tile?”
One way to do it is you could put a very hard plate [on the underside
of the tile]. You [could] put a piece of aluminum, or piece of graphite
epoxy, to dissipate [the] force that was [concentrated]. That would
have been a lot of weight to add to the vehicle, I mean a lot of weight.
So we tried to do different things.
An engineer by the name of Glenn [M.] Ecord in the materials group one
weekend came up with the solution. This falls under the title of “necessity
is the mother of invention.” We had to find a solution. Glenn
took real real fine silica powder, like talcum powder fineness, and
put it in distilled water, nothing more than that, and then [brushed]
this colloidal solution of silica powder on the bottom of a tile. Little
grains of silica would just embed themselves amongst all the fibers
in the tile, and when they dried it was like putting a little barrier
of real densified silica right there. [The powdered silica] adhered
to the silica fibers, and that provided the strength that we needed
on the bottom of the tile. It literally doubled or tripled the effective
strength of the tile by dissipating that concentrated load into the
rest of the tile. We had to take the tiles off the vehicle and apply]
this [process]. That was a good [solution to a major problem]. Necessity
is the mother of invention, and [there are] a bunch of cases in the
Shuttle where that is [proven].
The next thing in the tiles—I think I may have mentioned this
before. John [F.] Yardley was the Associate Administrator all through
Shuttle [development]. John Yardley started his career as a stress engineer
at McDonnell Douglas. He was a very very good engineer. He was probably
one of the best managers I’ve ever worked with in my life. John
says, “Okay, you smart guys, now you got the tiles bonded, how
do you know that they’re bonded good enough?” That was the
next step. He said, “It’s a very people-dependent thing,
because it’s a function of mixing up the adhesive, applying the
adhesive properly, bonding it properly. It’s a people [driven]
process. If not done properly, you lose the tile, lose the tile in the
wrong place, you lose the vehicle.”
So we developed a scheme [with] which [to verify a good bond]. We attached
a suction cup to the tiles and pulled on each tile. His next question
to us was, “How do you know you didn’t do more damage pulling
on it,” [that is], decrease the integrity of the bond of the tile?
What we did was we put microphones [on] tiles in the test lab. We pulled
on them, [recorded the] noise. We gathered enough data to know if it
[withstood the load and] only made so much noise, it had the necessary
Those are the kinds of things that finally got us over the hurdle. Now
we’ve got 25,000 tiles on the vehicle. Let’s show that we
have the required structural integrity on all 25,000 tiles to say that
we’re ready to fly the first mission. We went through a complicated
[logic] matrix. I think I left a copy of that with you. We have a process
to certify every tile that it had sufficient strength margin to fly.
Some of which we did by analysis, some we pulled to show that we had
enough strength. Others we couldn’t get [access] to but we showed
we had really big [strength] margins. Others we said, “We think
we got enough margin, but if it fails it’s not going to be a catastrophic
failure.” We went through all 25,000 tiles, late in the program,
“Yea verily,” at the flight readiness review [we were able
to say], “we’re ready to fly.”
That was the character of NASA program management then. You had to be
willing to convince the people you were talking to, the decision makers,
that you knew what you were doing, and you were right. The way you would
convince them, or the way they would convince themselves that you were
okay, they just kept probing and probing and probing and probing. You
had to be able to explain yourself in a simple way, but with enough
data and enough confidence that you could convince them you were right.
We put together a pretty comprehensive story on all 25,000 tiles, and
it withstood a lot of scrutiny. We said, “Yea verily, we’re
ready to fly.”
First flight came. We lost seven tiles, but they were in a region that
was not very high-temperature. We didn’t do any damage to the
vehicle at all when we lost them, but it gained a lot of national publicity
when those tiles came off.
That was it, [the story of the tiles]. We had our back against the wall.
We were the pacing item on the first launch. Everybody else was ready
to go, and assuring those tiles were attached was the thing that was
pacing [the program].
much time did you spend out in [Palmdale] California and then Florida
[NASA Kennedy Space Center] as they were putting the tiles on and taking
them off and putting them back on again?
not a simple answer to that, but let me tell you what we did every single
day. Every morning at 7:30 we had a meeting. We understood exactly who
was doing what, what progress they’d made and what problems they
had, both in California and in Florida and in Houston [at JSC]. It was
primarily in Florida, because that’s where the final [manufacturing
and assembly] of the vehicle occurred. We felt it wasn’t being
done as good in Palmdale as it could have been in Florida, so we moved
all the operations there. A person by the name of Kenny [Kenneth S.]
Kleinknecht was the JSC resident guy at the Cape [Canaveral, Florida].
It was a small group, but every morning at 7:30 Chris [Christopher C.]
Kraft, Aaron Cohen, myself, Kenny Kleinknecht, and maybe two or three
others depending what the issues were and what [was planned from] the
previous day [met to determine the status, resolve issues, and determine
what was to be accomplished that day]. Every morning we met at 7:30
until that vehicle flew.
understand that they were working long hours, long days. Can you tell
us, did people from California move out to Florida at that time period?
probably not the right person to answer that because I don’t know
about those problems. It doesn’t surprise me that they had problems
doing that, but I’m not aware of the difficulty there. We had
one other little thing. As we went through all this couple years of
these issues and problem solving that I just told you about, we had
some outside experts “helping” us.
was going to ask you about that.
Moser: These outside
experts weren’t people involved in the actual program at JSC.
We had some people on there from [NASA] Langley Research Center [Hampton,
Virginia], [and a] big group of people from academia. I don’t
remember how large it was. It [the TPS group] was one of the groups
under Walt Williams [NASA chief engineer] looking at the entire vehicle
before first flight. We spent a lot of time, in addition to solving
our problems, educating that outside group and convincing them. This
wasn’t a matter of weeks, this was a matter of months that we
worked with all these people.
We would go back and forth between here and the West Coast and Langley
Research Center. We finally got everybody to feel comfortable with it.
Some of the guys at Langley Research Center thought it would be best
to do a wind tunnel test of tiles around the forward attachment of the
Orbiter to the external tank. It was a fairly complicated aerodynamic
region, and they wanted to do some testing in that area. We at JSC,
the guys that were responsible, didn’t think it was really necessary
to do [the test]. We thought, “No, we think we’ve got this
covered. We understand it well enough, we understand all the loads on
it, and we’ve got enough margin.” But they kept insisting
and throwing up red flags, so we said, “Okay we’ll do the
When I say okay we’ll do the test, our project manager had to
agree with it, Aaron Cohen—and Chris Kraft even agreed with it.
We did it to “satisfy the concern.” We didn’t probably
tell John Yardley about it though. We didn’t hide it from him,
we just were doing our job. Well, John heard about it, and we were all
down at the Cape and he said, “I want to meet with you guys at
7:30 tomorrow morning at breakfast.” “You guys” were
Chris Kraft, Aaron Cohen and myself. We met with him at breakfast, and
he was livid because this was a matter of a couple weeks before the
As any good engineer or engineering manager would think, if something
goes wrong you’re going to shut this whole thing down. Boy, he
[Yardley] went up one side of us and down the other. He just ate us
alive, which he could do. Aaron and I sat there, and we didn’t
say anything because we didn’t want to do the test. But Chris
Kraft agreed with the Center Director of Langley to do it. Chris said,
“They didn’t want to do it; I agreed to do it.” We
hadn’t run the test [at that time]. We said, “John, it’s
okay.” So we had to convince him that what we had done [was okay].
He would probe and probe and probe, like all NASA managers would do.
They’d probe and probe and probe and probe based on their experience,
and if you didn’t have the right answer every time, then you probably
weren’t going to get across the goal line. Well, we got across
the goal line. Long story short, the [test was successful and the] vehicle
Almost two or three days before the first flight, Chris Kraft called
Don [Donald P.] Hearth, who was the Center Director at Langley, and
said, “Don, is there anybody at Langley Research Center that has
any issue or any concerns about this flight and about the thermal protection
system?” Don Hearth said, “Let me go check. I’ll go
run the trapline and I’ll call you back.” He called back
and says, “No, we’re good to go.”
The day before the flight a person comes out of the woodwork, says it’s
going to fail. “Tiles are going to come off, you’re going
to lose the whole vehicle, and here’s how it’s going to
this Holt Ashley?
Moser: No, it was
It was frustrating because Chris [Kraft] took us up there, [and] we
would work, work, work, work, work, and then Chris, being from that
area, we’d all go to dinner. We grew to know one another. It was
a lot of respect for one another and a lot of technical camaraderie.
We thought we had it pretty well covered.
was going through some TPS [thermal protection system] documents and
in one of the memos Holt Ashley suggested that you had to search for
a SIP replacement. Do you recall that?
Moser: Never did.
Not so, no. Probably Holt was talking about, “What can we do to
eliminate the stiff spot in the SIP? Is there another way to dissipate
that stress concentration?” Holt was a good guy. He was a good
ally on a lot of technical issues like this. That’s probably what
Holt was talking about. I’m sure it was. Probably looked at some
other SIPs but I don’t remember specifically what it was. You
can see the problem there; now you had a whole series of tons of thermal
performance tests and everything else that had that SIP in it. If we’d
changed the SIP, we’d have had to change processes, we’d
have had to change recertification. What Glenn Ecord did, he found this
magic solution that saved the bacon.
did the tiles perform on the next few orbital test flights?
They performed great. Not perfect, [but] they performed great. I’d
have to go back and look at the history. We lost a few tiles, none of
any consequence. On the chine of the Orbiter we lost a tile. It got
hot enough to cause a little bit of deformation in the structure, but
it was repaired. It was not permanent. We never did anything that permanent[ly]
damage[d] the vehicle. There were a few places where we lost some tiles,
but of no consequence. Today I don’t think there’s any [tiles
We knew that the glass coating, borosilica I think is what it is, on
the tiles was paper-thin and more fragile than an eggshell. We thought
that we’d probably have to replace about 10 percent of the tiles
on the vehicle every flight just because of handling damage, but that
was never the case. People learned how to work around them and be careful.
I don’t know how many are replaced today but probably not too
many. I think at one time some were taken off every flight just to get
some flight data on them. How good are they, go pull them until they
fail, inspect them. I think there’s a lot of confidence [that’s]
been gained in the tiles. Today there’s probably ways to make
a tile more [damage] tolerant.
Let me back up and say another thing about tiles, and maybe I said this
before. The tiles were designed for a lot of severe environments. Remind
me to send you that technical paper on the
Strength Integrity of the Space Shuttle Orbiter Tiles], it’s
pretty good. It shows all of the wind loads, the vibration loads, the
deformation of the structure. If the structure deflects underneath the
tile 90/1,000 of an inch, the tile will fail. It has a lot of various
things that have to be considered.
It was designed for all those environments, but was never ever designed
for any debris. To this day it’s not designed for debris. It’s
not certified for debris. After the Columbia accident [STS-107]—one
of the guys responsible for the tiles and I communicated a lot during
that time. He said that there was some push to say that debris impact
was okay. And I said, “No, you can’t say that. There’s
three choices. Number one, you can redesign so that it is good for that.
Or you can recertify. Or the program direct manager can make a decision
that it’s acceptable risk. The first two you can do. The third
one you can’t, that’s their [the managers’] decision.
For you to recertify for that environment is huge.”
That was a major issue. Today I think the program management has better
criteria on what kind of debris impact they can take, [i.e.] knowing
that there will be some damage. So they’re able to fly the vehicle,
but it was not designed and certified for any debris, period.
you involved at all in the discussions about repairing the thermal protection
system in space?
Moser: A little
bit, but not intimately involved in it, no. That was more [about] different
materials to apply. After the first few flights we did some stuff on
repair techniques, but we dropped it just because it didn’t look
like anything was panning out. [There were] places on the vehicle you
couldn’t get to—we even looked at a little flyaround vehicle
to inspect, and even have some capability to do repairs. But we were
getting more flights underneath our belt, and we thought we’re
not going to ever go there [with a capability to repair the TPS]. I
didn’t get involved in any of the details after Columbia on tile
you in the Mission Control Center when they found out that they were
missing some tiles? Was that a major issue for your group that you remember?
Moser: I was at
the Cape on STS-1. When we got the word [from the crew] that we lost
some tiles, I was told to go get on a Learjet and get back to Houston
and figure out what the problem was and what we were going to do. So
that’s what I did, came right back to Houston and we convinced
ourselves everything was okay, and why we were okay. And that was it.
a big deal?
Moser: It wasn’t
really a big deal. We knew where it was, but we did our engineering
pretty thoroughly for about a day or day and a half, something like
that, and said, “We’re okay,” and come on back in.
Then we had a press conference. I think it was Gene [Eugene F.] Kranz
and myself and Don [Donald R.] Puddy as I recall. The media was firing
a lot of questions.
were they asking?
Moser: They wanted
to be convinced why it was okay. The media is interesting in those days,
and I think probably today. They had really done their homework on all
this stuff. They knew about all the problems we’d been through,
so they asked some penetrating questions. Had to convince them too,
or you’d get bad press. Bob [Robert F.] Thompson used to always
say, “The best interview is one which you never read about in
the paper.” If it doesn’t get written, that’s a fantastic
interview. Any time he gave interviews and he wasn’t quoted, he
felt he was successful.
us about moving over to the Orbiter Project Office. What changed? You
were in engineering management, and then you became project management.
on the Shuttle in ’69 so was there, as I said [in the first interview],
“sketch pad to launch pad.” After the first few flights
I was the section head in Structures and Mechanics Division. Then I
was asked to be Chris Kraft’s “horse holder” [technical
assistant]. Didn’t know what that job entailed. I called somebody
that had done it before and said, “I just got this call.”
He said, “You were asked to do it?” I said, “Yes,
I’m trying to decide if I want to.” He said, “You
do want to. You want to do that.” That was a fantastic experience.
Chris had this program where your job was to observe. You didn’t
really produce too much. He just selected some people, and he just wanted
them to be around him and see—from that level and from that vantage
point—how the Center worked.
Then I was asked to be the deputy Orbiter project manager when Aaron
was the project manager. I served in that capacity. What we were doing
then—the vehicle was essentially developed. We were just in the
early operations phases, so I was there just making sure that the vehicle
was ready, all the flight readiness preparation was in place. We had
the right flight rules—one of the things that was important about
the early flights [was to make sure that the vehicle flew within the
From an Orbiter perspective, [the project] started with a lot of really
large, complex test vehicles. There was a vehicle or [thermal vacuum]
test article planned for the forward-fuselage of the Orbiter—everything
from the payload bay forward, including the cabin, all the forward-fuselage,
and all the systems in it. And it was going to be [tested] in the thermal
vacuum chamber at JSC. Everything aft of the payload bay, with all the
propulsion systems and everything else in there, was going to be a test
article. These were just dedicated test articles.
There were to be two Orbiter airframes, that’s [a complete] structure.
One [test article] to show that you could take the maximum load expected
and then increase that by 40 percent to 140 percent of maximum load before it would
fail. The other one was a fatigue test [article]. These structural tests
were just characteristic of the aircraft manufacturers; they have static
test article and fatigue test article.
Because of reductions in budget, we had to be creative, like Ecord was
with the silica and densifying the tiles. We had to figure out a way
to not compromise the safety or the integrity of the vehicle but convince
ourselves without some of these expensive test articles we could [test
and then] fly them. So we said, “Okay, we think on the thermal
performance we can start off a little bit more benign the way we [design
the mission and] fly it. We will “barbecue” [rotate] the
vehicle in space to make sure that it [keeps a] more uniform temperature.
We will try and be as lightly loaded thermally as we possibly can, and
we’ll gradually increase the envelope to more severe and severe
and severe conditions.” The Orbiter Project, we had to make sure
that the flight profile was doing exactly that, we were sneaking up
on it slowly.
The same thing with the structural tests; we eliminated both of the
structural test articles. Challenger vehicle is what we [structurally]
tested. I may be repeating some stuff from the previous interview. When
we decided to do that it wasn’t good enough just to say we’re
good to go, and it wasn’t good enough to just convince John Yardley,
we had to convince an outside group made up of aircraft manufacturing,
people who made the [Boeing] 747, the [McDonnell Douglas] DC-10, the
[Lockheed] L-1011, those class [of aircraft]. They brought a group of
their structural experts in and we had to convince them what we were
planning to do was okay.
What we planned to do was to load the vehicle slowly up to 120 percent of the
maximum mechanical load or airload, if you will, and inertia load. A
strain gauge measures the strain in the vehicle [structure]. If I put
one on the table right here it would read zero. If I start bending the
table, the amount of bending that I put in is how much strain that gauge
is going to measure. We had to prepredict, I think it was like 3,000
strain gauges, what they were going to do as we loaded this vehicle
in a lot of different ways. If we could do that, then we could say,
“Well, we can extrapolate to 140 percent.” We did that—prepredicted,
everything was cool, we extrapolated [to show the structure could withstand
the ultimate load].
[The static structural test article flew as the] Challenger vehicle.
We saved $100 million one year by eliminating that [dedicated] test
article. But again we had to fly the vehicle [in the] early flights,
make sure we were sneaking up on those [design] loads. We didn’t
get any surprise, and it all worked. The early flight phases, when I
was the deputy project manager, that was our focus. Then I stayed in
that position for a couple years, then I became director of engineering.
they were integrating the vehicle[s] in California—we had Challenger
[OV-099], Discovery [OV-103], Atlantis [OV-104]—what was your
role as they were producing them, manufacturing them, and then sending
them over to the Cape?
where the contractor has all the capability and expertise that the NASA
guys don’t have. They have the capability to do the detailed design
and manufacturing that NASA doesn’t have, nor should they have.
We would just work with them when problems and issues came up. A lot
of times during that phase of a program there are “make work”
changes being made. We didn’t change anything [in the basic design].
That was the thing that the Orbiter Project never allowed, and that
was to Aaron’s credit. He could say “no” more firmly
than anybody in the entire world. It was no, no, no [to changes with
the design]. So we weren’t spending a lot of our time with [North
American] Rockwell [Corporation] implementing changes, it was just if
problems would occur or something like that. We didn’t get too
much involved in the actual day-to-day stuff. Didn’t want to,
didn’t need to, and we were off working other things.
no difference between any of the Orbiters in the fleet?
Moser: Yes, there
are. We had to take some weight out of the vehicle; there were changes
made as it progressed. But relative to the early development they were
minuscule, and they were very gradual and very slow evolution. Each
one of them is a little bit different, but not significantly. There
were some process problems. The payload bay doors, for instance. I think
that they were changed into a more efficient manufacturing way, since
it was all graphite epoxy. That was not a macro change, I take that
as a detail change.
I don’t remember any other significant change. The reason I said
Aaron kept saying “no, no, no” is once we froze the design
in ’72 and says that’s it, then if we had a problem it was
a make-work change. Little bit thicker material here, something of that
sort. People were constantly proposing changes to make the vehicle better.
The RCS [reaction control system] jets, a group of people wanted to
move those out to the tips of the wings. So now you can see, [if] you
got a little bit of thrust out there, you can move the whole vehicle
real easy as opposed to back where they’re located up close to
or on the fuselage now. But the answer was no.
Somebody else wanted to put canards—that’s a little wing
on the front of the vehicle [to] give it more aerodynamic stability—the
answer was “no—not going to do it.” The only real
change that we made was we added a head-up display so the astronauts,
as they looked out the windshield, could see the critical elements that
they need to in flight for their control systems. That was key. “No,
no, no, no, no, not going to make any change.”
other activities occupied your time in that position?
Moser: As the deputy
that was it primarily. It was in supporting flight operations and making
sure it was compatible between the vehicle design capability and the
way the vehicle was going to be flown.
us about moving over to Engineering.
Moser: The Engineering
Directorate was a totally different thing. There you’re in line
management, you’ve got all the engineering disciplines involved.
In any development program that’s the key element to making a
system work. You have to work with the ops [operations] guys to make
sure the operations plans are compatible with the design and the right
Going into that large a spectrum of engineering was a big change, because
I had “grown up in the structures and materials area” and
now I had guidance, navigation and control, environmental control, communications.
It was a matter of, like any person at that level, you have to make
sure the people have the resources and the right guidance on where to
go, and get out of their way.
You have to support them, and at the same time you have to then be responsible
from the top down. Every year when a budget comes about, if you took
everybody’s wish it doesn’t fit. You have to be the bad
guy, you have to weigh what’s more important relative to where
the organization is going and where you want the Engineering Directorate
to go. Totally different thing, you’re not in the day-to-day projects.
I always sat in all the flight readiness reviews representing all the
disciplines in that respect. There was another thing too as the director
of Engineering. I was talking to some of the guys this morning as part
of the Space Systems Engineering Development Program, and the title
of this thing was dealing with change and all the change that they’re
going through now.
Space Station hadn’t been approved. We were wrestling with, as
the Director of Engineering representing all of those various disciplines,
“What is this Space Station going to be?” I spent a lot
of time on the requirements for Space Station. We needed to understand
requirements—how are we going to manage it, what is the organization
going to be, what is each Center’s responsibility going to be.
I spent a lot of time with that, but that program wasn’t approved.
In the meantime, we’ve got 650 engineers in the Engineering Directorate,
and not doing a lot of developing. So Chris Kraft, the Center Director,
says, “Okay, what we’re going to do, we’re going to
move a lot of the Engineering Directorate guys over to ops, because
that’s where the focus is.” There was ranting and raving
and kicking and screaming. People don’t like to change. He knew
that was the right thing to do, so he moved a good number of them over
there. We needed to keep our tools honed and in good shape in all the
structural disciplines so we started looking for flight projects. The
vehicle was flying so Aaron and I became the “chief salesmen”
for Johnson Space Center [engineers] on flight projects. We went around
knocking on doors of anybody at NASA that had any money and we said,
“What help do you need?”
Somebody asked us one day—I think it was the Associate Administrator
for Space Sciences. He said, “Well, what are you guys good at?”
We [Aaron and I] looked at one another and we said, “Everything,”
because we had the full spectrum [of engineering disciplines]. We weren’t
aerodynamicists particularly, we weren’t heat transfer guys, we
were good at all those things. Because we hadn’t thought about,
we didn’t have a brochure that says, “Here we are.”
We weren’t good at marketing.
We got small projects. We got a project that we designed and built in
house, an orbital fuel transfer system. General [James A.] Abrahamson
was the Associate Administrator [of Space Flight] at the time. He wanted
to show you could take hydrazine and move it from one tank to another
[while] in space. It involved the crew, so we designed and built this
experiment to put in the payload bay of the Orbiter. Those are the kinds
of things we designed and built in house.
What I did to fill this void between Shuttle and Space Station, I formed
a Flight Projects Office. It was a project office for a bunch of little
projects. That group in the Engineering Directorate then had all the
other divisions working with [them] to do things, like this experiment
that I just told you. Then we integrated some synthetic aperture radars
in the vehicle, which required a lot of engineering.
We were looking for work. Marshall [Space Flight Center, Huntsville,
Alabama] was doing the same thing. They worked on railroads, and they
worked on trusses and trestles and minimizing earthquake damage to buildings.
NASA was running around looking for stuff to do during this hiatus between
Shuttle and Space Station.
On your vita you mentioned two specific missions that stood out, one
of which was the Solar Max satellite, STS-41C, and the other was STS-51A—you
had shown Rebecca a photo.
Moser: Yes, that
was Joe [Joseph P.] Allen. That was the satellite recovery of WESTAR
and PALAPA satellites. I was director of Engineering at that time. That
was another thing that we did in house. We designed and built the tools
with which to go out and capture the satellite. I think what I mentioned
was when I was sitting in Mission Control looking at this process going
on, it was like this guy going out with a harpoon getting ready to stick
it into this satellite.
I said, “That’s a modern-day whaling scene.” It’s
a guy going with a harpoon in a harsh environment trying to capture
an unwilling creature. So I had some of the guys over in the graphics
[department] superimpose a modern-day whaling scene with Joe Allen with
the harpoon on an old-day whaling scene, the guy with the boat with
the harpoon. Here it is, all integrated into one picture. I think Joe
Allen has got a copy of it, and I’ve got a copy of it. I don’t
know if anybody else does or not, but that was one of the things in
the Engineering Directorate. That was another one of the projects. As
other problems came up on the Orbiter like that or another mission,
we did that.
I was director of Engineering during Solar Max repair. I think I was
Chris’s horse holder when that idea came up. Maybe it came up
there, but then I was director during the implementation of it.
you ever do anything when the crew was in space, and they needed something,
like an Apollo 13 event? I’m thinking of the Flyswatter event
for instance [STS 51-D].
Moser: Yes, there
were a few things like that but to tell you the truth I don’t
remember the specifics of them. There’s always something like
that. There’s always real-time things that you have to put your
engineering hat on and go solve or say it’s not a problem. We
had ice form on the part of the cooling system and had to get rid of
that and cap it off. But I didn’t see those as big challenges.
do you think were some of the milestones of the program until the Challenger
accident [STS 51-L]?
Moser: I don’t
think there was a major milestone. I think it was a slowly evolving
program to establish the capabilities of the vehicle. The vehicle was
designed for four people for seven days. So 28 person-days in orbit
is what the vehicle was designed for. The first vehicle had a couple
of ejection seats in it, crew of two. We started with that and gradually
evolved into determining the capability of the vehicle. We’ve
flown seven people. The maximum that we’ve flown just in the Orbiter
itself had been seven people for two weeks or something like that. That’s
98 people-days, when it was designed for 28.
What we did is just kept expanding the knowledge of the capabilities
of the vehicle and doing that. The other thing we did is found out how
to better accommodate payloads. NASA had a terrible image with the payload
community early on about it was a privilege to get to fly in this vehicle.
We worked very hard at trying to simplify the way we integrated payloads,
both in an active sense—in active systems, cooling and power—but
also in just structural accommodations. That took a lot of our time.
To my way of thinking, there weren’t major milestones. It was
just a gradual increase in all the capabilities was accomplished during
that [time frame].
mentioned to Rebecca and Sandra [Johnson during the first interview]
that you were in the Mission Control Center for the last flight of Challenger.
Would you share with us your recollections of that day?
Moser: Yes, that
was not a good day. As a matter of fact I was not on the floor in mission
control. I was up in the VIP area, as was Chris Kraft on my left and
Aaron Cohen on my right. We were sitting there and it was getting to
be “Okay, we got this thing by the seat of the pants.” We
weren’t complacent; we’d gone through every check on every
flight. And we saw what happened. As soon as we saw the vehicle encounter
that—not explosion, but it was like an explosion—all three
of us thought it was probably the main engines because that was always
the thing we worried about most, the high-pressure high-speed turbopumps
and everything else in those engines. We thought that that was it.
We went over and looked at films that we got very early on. Within a
few hours we knew what it was. We knew it came from the solid rocket
motors. Then I led an internal group of failure investigation. We started
that process, and within a matter of a few days we had it nailed. We
knew exactly what it was.
The only fortunate thing in any of that, was we could clearly define
what the failure was; therefore, we knew what to fix. Had that failure
been in the main engines, it may have canceled the program because we
may not have ever found out exactly what it was. We didn’t have
that much instrumentation, [and] that much [detailed information].
We had some fixes that we think would have worked, and we could have
been flying again very quickly, like after the Apollo  fire. I think
it was what, eight months from the time of that and a lot of redesign
on the Command Module, I mean a lot of redesign, and we were flying
again. It took us two years [after Challenger before we flew again].
Bureaucracy took over, and it’s just too bad.
Extrapolating on that, Apollo Program was eight plus years from go [ahead]
to fly. Shuttle Program, ’72 to ’81, nine years from start
of development to flight. We’re 23 years in the Space Station,
and it’s just now being completed. Let’s take out four years
for Columbia and Challenger, because two years down in both of those
programs—that’s still 19 years.
Bureaucracy is catching up. I have this theory called the “conservation
of complexity.” The conservation of complexity is when you take
the technical issues and the political issues and you put them together,
that forms a complexity unit. Apollo [had] huge challenges technically.
I mean huge, beyond belief. We didn’t even know what we didn’t
know. I mean period we didn’t know what we didn’t know.
But the political environment was very simple. President was for it,
the Congress was for it, there wasn’t a lot of bureaucracy and
we moved on and we did it.
Fast-forward now to Shuttle. Shuttle came along. Shuttle had some technical
issues—thermal protection system, the main propulsion system and
the avionics—three major state of the art advancements. Simpler
technically, but more complex politically. I’m still maintaining
my [conservation of] complexity.
Space Station comes along. Developmentwise, technically, there’s
nothing to Space Station. Yes, there’s a lot of operations that
have to be planned and details, and it’s dangerous, and it’s
complicated—but nothing to develop, everything existed. But the
political environment is just horrendously terrible. Again, make my
case of “conservation of complexity.” You just plot this
graph which I have, and it shows we’re falling right in line.
Then Constellation comes along, and [it is more complex technically
and politically]. If you do Constellation the way the Constellation
Program is defined, yes, there’s some technical challenges on
how people live and work effectively on the lunar surface, but there
are no major technologies as far as propulsion or anything like that.
It’s trying to use “off-the-shelf” stuff there, but
the political thing is very complicated. What we have today is all of
a sudden this Constellation thing has just exploded [politically]. We
don’t know what it is or where it’s going to go. It may
condense back down to Constellation. I don’t believe that’ll
happen, but there’s some good parts of that too.
When we were talking about John Yardley made the decisions and Chris
Kraft and Aaron Cohen—all these guys had full confidence in themselves
because they’d been there and done that on a lot of things. I
had the good fortune of getting to do a lot of things where we designed,
built stuff, and blew things up. You learned by doing those things.
What’s being proposed is a group of technology initiatives. [They]
are not going to just be in the laboratory, [experiment] and analysis.
[The engineers have] to design, build, and test things. That can be
very good for the thing [because] NASA has gotten away from learning
I think that some of the deficiencies in some of the decision making
from what I can see at NASA today, is people are having a hard time
making decisions. It could be, too, because they’re living in
the post-Columbia-Challenger environment where they’re careful,
they’re more afraid to make decisions than probably they could
be, should be. So with these other small [technology institutes]—we
call them small, they’re going to be pretty large—they’re
going to be things where you design and build things and go fly them.
That’s going to be very good if that comes about.
[End of interview]
this link to view all the photos in Thomas L. Moser's photo gallery.
to JSC Oral History Website